Autor: Britton & Rose

Genus honouring Thomas Hariot (also written Harriot, 1560-1621), English mathematician, astronomer and naturalist (see picture above). Hariota having been invalidated, Britton & Rose created the name from an anagram of Hariot, Hatiora (see portrait above, public domain).
A genus of epiphytic or more rarely lithophytic plants, strongly branched, at first erect then pendulous, with short segments well determined, cylindrical or bottle-shaped, not tuberculate and acrotonic. Areoles tiny, spines usually absent or setose when present.
Flowers diurnal, self-sterile, appearing at the tip of stems, heteromorphic, with a very short floral tube, bell-shaped, yellow to yellow orange-coloured, or pink, pollinated by insects. Pericarpel rounded, naked. Fruits small, spherical, naked. Seeds small, shiny, brown or black.
The genus Hatiora grows in ombrophilous rainforests of southern Brazil, as epiphytic, taking advantage of some organic matter deposited in the hollows of trunks and branches, from 300 m up to 1500 m in altitude. This region has a significant atmospheric humidity.
Brazil (Bahia, Espirito Santo, Minas Gerais, Parana, Rio de Janeiro, Sao Paulo).

Currently 3 recognised species:
– Hatiora cylindrica* Britton & Rose Britton & Rose 1923
– Hatiora herminiae* (Porto & A.Cast.) Backeb. ex Barthlott 1987
– Hatiora salicornioides* (Haworth) Britton & Rose ex L.H.Bailey 1915

References: "TAXONOMY of the CACTACEAE" -  ISBN 978-84-617-3723-9 (Vol. 1)